The UK's aggregate defined benefit deficit increased over March to £115.6bn from £72.1bn on a section 179 basis, according to Pension Protection Fund estimates.
Scheme asset values remained largely unchanged over the month, while liabilities increased from £1.64tn to £1.68tn.
That leaves them 93.1 per cent funded against the cost of securing PPF-level benefits with an insurance company, down from 95.6 per cent at the end of February.
The increase in deficits was driven by a 19 basis point fall in the yield on conventional 15-year gilts, while the impact of lower equity prices on asset values was mostly offset by the increase in bond prices.
The funding level represents a marked improvement on a yearly basis. At the end of March 2017, the UK was 90.5 per cent funded with a deficit of £161.8bn.
This article has been corrected to amend a mistyping of section 179.
